Make Yes the default for git-mrb, fits regular workflow much better.

tools/git-mrb

@@ -1,80 +1,80 b''
 #!/usr/bin/env python
 """git-mrb: merge remote branch.
 
 git mrb [remote:branch OR remote-branch] [onto] [upstream]
 
 remote must be locally available, and branch must exist in that remote.
 
 If 'onto' branch isn't given, default is 'master'.
 
 If 'upstream' repository isn't given, default is 'origin'.
 
 You can separate the remote and branch spec with either a : or a -.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from subprocess import check_call
 import sys
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 def sh(cmd):
     cmd = cmd.format(**shvars)
     print '$', cmd
     check_call(cmd, shell=True)
 
 #-----------------------------------------------------------------------------
 # Main Script
 #-----------------------------------------------------------------------------
 
 argv = sys.argv[1:]
 narg = len(argv)
 
 try:
     branch_spec = argv[0]
     sep = ':' if ':' in branch_spec else '-'
     remote, branch = branch_spec.split(':', 1)
     if not branch:
         raise ValueError('Branch spec %s invalid, branch not found' %
                          branch_spec)
 except:
     import traceback as tb
     tb.print_exc()
     print __doc__
     sys.exit(1)
 
 onto = argv[1] if narg >= 2 else 'master'
 upstream = argv[1] if narg == 3 else 'origin'
 
 # Git doesn't like ':' in branch names.
 if sep == ':':
     branch_spec = branch_spec.replace(':', '-')
 
 # Global used by sh
 shvars = dict(remote=remote, branch_spec=branch_spec, branch=branch,
               onto=onto, upstream=upstream)
 
 # Start git calls.
 sh('git fetch {remote}')
 sh('git checkout -b {branch_spec} {onto}')
 sh('git merge {remote}/{branch}')
 
 print """
 *************************************************************
  Run test suite.  If tests pass, run the following to merge:
 
 git checkout {onto}
 git merge {branch_spec}
 git push {upstream} {onto}
 
 *************************************************************
 """.format(**shvars)
 
-ans = raw_input("Revert to master and delete temporary branch? [y/N]: ")
-if ans.lower() in ('y', 'yes'):
+ans = raw_input("Revert to master and delete temporary branch? [Y/n]: ")
+if ans.strip().lower() in ('', 'y', 'yes'):
     sh('git checkout {onto}')
     sh('git branch -D {branch_spec}')